Implement Empty method for host device vector. (#5781)

* Fix accessing nullptr.
2020-06-13 19:02:26 +08:00
parent 306e38ff31
commit 1fa84b61c1
3 changed files with 11 additions and 1 deletions
--- a/tests/cpp/common/test_host_device_vector.cu
+++ b/tests/cpp/common/test_host_device_vector.cu
@@ -176,6 +176,13 @@ TEST(HostDeviceVector, Span) {
  ASSERT_TRUE(vec.HostCanWrite());
 }

+TEST(HostDeviceVector, Empty) {
+  HostDeviceVector<float> vec {1.0f, 2.0f, 3.0f, 4.0f};
+  HostDeviceVector<float> another { std::move(vec) };
+  ASSERT_FALSE(another.Empty());
+  ASSERT_TRUE(vec.Empty());
+}
+
 TEST(HostDeviceVector, MGPU_Basic) {  // NOLINT
  if (AllVisibleGPUs() < 2) {
    LOG(WARNING) << "Not testing in multi-gpu environment.";